Add a Java interface (#9346)

* Add a Java interface

* Use system ABI

* Forgot exception

* Fix param for parity_rpc

* Address concerns

Cargo.lock

@@ -38,6 +38,11 @@ dependencies = [
  "nodrop 0.1.12 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "ascii"
+version = "0.7.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "assert_matches"
 version = "1.3.0"
@@ -175,6 +180,11 @@ name = "cc"
 version = "1.0.22"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "cesu8"
+version = "1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "cfg-if"
 version = "0.1.5"
@@ -239,6 +249,15 @@ dependencies = [
  "cc 1.0.22 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "combine"
+version = "2.5.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "ascii 0.7.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "byteorder 1.2.6 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "common-types"
 version = "0.1.0"
@@ -1353,6 +1372,24 @@ name = "itoa"
 version = "0.4.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "jni"
+version = "0.10.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "cesu8 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "combine 2.5.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "error-chain 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "jni-sys 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "log 0.3.9 (registry+https://github.com/rust-lang/crates.io-index)",
+ "walkdir 2.2.5 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "jni-sys"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "journaldb"
 version = "0.2.0"
@@ -1965,6 +2002,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 name = "parity-clib"
 version = "1.12.0"
 dependencies = [
+ "jni 0.10.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "panic_hook 0.1.0",
  "parity-ethereum 2.1.0",
 ]
@@ -2885,6 +2923,14 @@ name = "safemem"
 version = "0.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "same-file"
+version = "1.0.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "winapi-util 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "scoped-tls"
 version = "0.1.2"
@@ -3686,6 +3732,16 @@ name = "void"
 version = "1.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "walkdir"
+version = "2.2.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "same-file 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi-util 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "want"
 version = "0.0.4"
@@ -3856,6 +3912,7 @@ dependencies = [
 "checksum ansi_term 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ee49baf6cb617b853aa8d93bf420db2383fab46d314482ca2803b40d5fde979b"
 "checksum app_dirs 1.2.1 (git+https://github.com/paritytech/app-dirs-rs)" = "<none>"
 "checksum arrayvec 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)" = "a1e964f9e24d588183fcb43503abda40d288c8657dfc27311516ce2f05675aef"
+"checksum ascii 0.7.1 (registry+https://github.com/rust-lang/crates.io-index)" = "3ae7d751998c189c1d4468cf0a39bb2eae052a9c58d50ebb3b9591ee3813ad50"
 "checksum assert_matches 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "7deb0a829ca7bcfaf5da70b073a8d128619259a7be8216a355e23f00763059e5"
 "checksum atty 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)" = "9a7d5b8723950951411ee34d271d99dddcc2035a16ab25310ea2c8cfd4369652"
 "checksum backtrace 0.3.9 (registry+https://github.com/rust-lang/crates.io-index)" = "89a47830402e9981c5c41223151efcced65a0510c13097c769cede7efb34782a"
@@ -3873,12 +3930,14 @@ dependencies = [
 "checksum byteorder 1.2.6 (registry+https://github.com/rust-lang/crates.io-index)" = "90492c5858dd7d2e78691cfb89f90d273a2800fc11d98f60786e5d87e2f83781"
 "checksum bytes 0.4.9 (registry+https://github.com/rust-lang/crates.io-index)" = "e178b8e0e239e844b083d5a0d4a156b2654e67f9f80144d48398fcd736a24fb8"
 "checksum cc 1.0.22 (registry+https://github.com/rust-lang/crates.io-index)" = "4a6007c146fdd28d4512a794b07ffe9d8e89e6bf86e2e0c4ddff2e1fb54a0007"
+"checksum cesu8 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "6d43a04d8753f35258c91f8ec639f792891f748a1edbd759cf1dcea3382ad83c"
 "checksum cfg-if 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)" = "0c4e7bb64a8ebb0d856483e1e682ea3422f883c5f5615a90d51a2c82fe87fdd3"
 "checksum chrono 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)" = "45912881121cb26fad7c38c17ba7daa18764771836b34fab7d3fbd93ed633878"
 "checksum cid 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)" = "d85ee025368e69063c420cbb2ed9f852cb03a5e69b73be021e65726ce03585b6"
 "checksum clap 2.32.0 (registry+https://github.com/rust-lang/crates.io-index)" = "b957d88f4b6a63b9d70d5f454ac8011819c6efa7727858f458ab71c756ce2d3e"
 "checksum cloudabi 0.0.3 (registry+https://github.com/rust-lang/crates.io-index)" = "ddfc5b9aa5d4507acaf872de71051dfd0e309860e88966e1051e462a077aac4f"
 "checksum cmake 0.1.33 (registry+https://github.com/rust-lang/crates.io-index)" = "704fbf3bb5149daab0afb255dbea24a1f08d2f4099cedb9baab6d470d4c5eefb"
+"checksum combine 2.5.2 (registry+https://github.com/rust-lang/crates.io-index)" = "1645a65a99c7c8d345761f4b75a6ffe5be3b3b27a93ee731fccc5050ba6be97c"
 "checksum crossbeam 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)" = "24ce9782d4d5c53674646a6a4c1863a21a8fc0cb649b3c94dfc16e45071dea19"
 "checksum crossbeam-deque 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "f739f8c5363aca78cfb059edf753d8f0d36908c348f3d8d1503f03d8b75d9cf3"
 "checksum crossbeam-deque 0.6.1 (registry+https://github.com/rust-lang/crates.io-index)" = "3486aefc4c0487b9cb52372c97df0a48b8c249514af1ee99703bf70d2f2ceda1"
@@ -3937,6 +3996,8 @@ dependencies = [
 "checksum ipnetwork 0.12.8 (registry+https://github.com/rust-lang/crates.io-index)" = "70783119ac90828aaba91eae39db32c6c1b8838deea3637e5238efa0130801ab"
 "checksum itertools 0.5.10 (registry+https://github.com/rust-lang/crates.io-index)" = "4833d6978da405305126af4ac88569b5d71ff758581ce5a987dbfa3755f694fc"
 "checksum itoa 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)" = "5adb58558dcd1d786b5f0bd15f3226ee23486e24b7b58304b60f64dc68e62606"
+"checksum jni 0.10.1 (registry+https://github.com/rust-lang/crates.io-index)" = "5479b540809575c4d6e3e68be5cdc33e03e0ab3d2108479a65d0374f2e82c1b9"
+"checksum jni-sys 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "8eaf4bc02d17cbdd7ff4c7438cafcdf7fb9a4613313ad11b4f8fefe7d3fa0130"
 "checksum jsonrpc-core 8.0.1 (git+https://github.com/paritytech/jsonrpc.git?branch=parity-1.11)" = "<none>"
 "checksum jsonrpc-http-server 8.0.0 (git+https://github.com/paritytech/jsonrpc.git?branch=parity-1.11)" = "<none>"
 "checksum jsonrpc-ipc-server 8.0.0 (git+https://github.com/paritytech/jsonrpc.git?branch=parity-1.11)" = "<none>"
@@ -4059,6 +4120,7 @@ dependencies = [
 "checksum rustls 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)" = "cc9f2e05fd6a3ce1530cd5dbcc553d2f94d7749fe3e4f5b443668eddd842889e"
 "checksum ryu 0.2.6 (registry+https://github.com/rust-lang/crates.io-index)" = "7153dd96dade874ab973e098cb62fcdbb89a03682e46b144fd09550998d4a4a7"
 "checksum safemem 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "e27a8b19b835f7aea908818e871f5cc3a5a186550c30773be987e155e8163d8f"
+"checksum same-file 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)" = "10f7794e2fda7f594866840e95f5c5962e886e228e68b6505885811a94dd728c"
 "checksum scoped-tls 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "332ffa32bf586782a3efaeb58f127980944bbc8c4d6913a86107ac2a5ab24b28"
 "checksum scopeguard 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)" = "94258f53601af11e6a49f722422f6e3425c52b06245a5cf9bc09908b174f5e27"
 "checksum sct 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "1137b767bbe1c4d30656993bdd97422ed41255d9400b105d735f8c7d9e800632"
@@ -4147,6 +4209,7 @@ dependencies = [
 "checksum vergen 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "8c3365f36c57e5df714a34be40902b27a992eeddb9996eca52d0584611cf885d"
 "checksum version_check 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)" = "7716c242968ee87e5542f8021178248f267f295a5c4803beae8b8b7fd9bc6051"
 "checksum void 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)" = "6a02e4885ed3bc0f2de90ea6dd45ebcbb66dacffe03547fadbb0eeae2770887d"
+"checksum walkdir 2.2.5 (registry+https://github.com/rust-lang/crates.io-index)" = "af464bc7be7b785c7ac72e266a6b67c4c9070155606f51655a650a6686204e35"
 "checksum want 0.0.4 (registry+https://github.com/rust-lang/crates.io-index)" = "a05d9d966753fa4b5c8db73fcab5eed4549cfe0e1e4e66911e5564a0085c35d1"
 "checksum wasmi 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "9b4a6d379e9332b1b1f52c5a87f2481c85c7c931d8ec411963dfb8f26b1ec1e3"
 "checksum webpki 0.17.0 (registry+https://github.com/rust-lang/crates.io-index)" = "9e1622384bcb5458c6a3e3fa572f53ea8fef1cc85e535a2983dea87e9154fac2"

parity-clib/Cargo.toml

@@ -12,6 +12,7 @@ crate-type = ["cdylib", "staticlib"]
 [dependencies]
 panic_hook = { path = "../util/panic_hook" }
 parity-ethereum = { path = "../", default-features = false }
+jni = { version = "0.10.1", optional = true }
 
 [features]
 default = []

parity-clib/Parity.java

@@ -0,0 +1,63 @@
+// Copyright 2018 Parity Technologies (UK) Ltd.
+// This file is part of Parity.
+
+// Parity is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Parity is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Parity.  If not, see <http://www.gnu.org/licenses/>.
+
+package io.parity.ethereum;
+
+/**
+ * Interface to the Parity client.
+ */
+public class Parity {
+    /**
+     * Starts the Parity client with the CLI options passed as an array of strings.
+     *
+     * Each space-delimited option corresponds to an array entry.
+     * For example: `["--port", "12345"]`
+     *
+     * @param options The CLI options to start Parity with
+     */
+    public Parity(String[] options) {
+        long config = configFromCli(options);
+        inner = build(config);
+    }
+
+    /** Performs a synchronous RPC query.
+     *
+     * Note that this will block the current thread until the query is finished. You are
+     * encouraged to create a background thread if you don't want to block.
+     *
+     * @param query The JSON-encoded RPC query to perform
+     * @return A JSON-encoded result
+     */
+    public String rpcQuery(String query) {
+        return rpcQueryNative(inner, query);
+    }
+
+    @Override
+    protected void finalize​() {
+        destroy(inner);
+    }
+
+    static {
+        System.loadLibrary("parity");
+    }
+
+    private static native long configFromCli(String[] cliOptions);
+    private static native long build(long config);
+    private static native void destroy(long inner);
+    private static native String rpcQueryNative(long inner, String rpc);
+
+    private long inner;
+}

parity-clib/src/lib.rs

@@ -17,6 +17,8 @@
 //! Note that all the structs and functions here are documented in `parity.h`, to avoid
 //! duplicating documentation.
 
+#[cfg(feature = "jni")]
+extern crate jni;
 extern crate parity_ethereum;
 extern crate panic_hook;
 
@@ -26,6 +28,11 @@ use std::ptr;
 use std::slice;
 use std::str;
 
+#[cfg(feature = "jni")]
+use std::mem;
+#[cfg(feature = "jni")]
+use jni::{JNIEnv, objects::JClass, objects::JString, sys::jlong, sys::jobjectArray};
+
 #[repr(C)]
 pub struct ParityParams {
 	pub configuration: *mut c_void,
@@ -117,7 +124,7 @@ pub unsafe extern fn parity_destroy(client: *mut c_void) {
 }
 
 #[no_mangle]
-pub unsafe extern fn parity_rpc(client: *mut c_void, query: *const char, len: usize, out_str: *mut c_char, out_len: *mut usize) -> c_int {
+pub unsafe extern fn parity_rpc(client: *mut c_void, query: *const c_char, len: usize, out_str: *mut c_char, out_len: *mut usize) -> c_int {
 	panic::catch_unwind(|| {
 		let client: &mut parity_ethereum::RunningClient = &mut *(client as *mut parity_ethereum::RunningClient);
 
@@ -163,3 +170,98 @@ impl CallbackStr {
 		}
 	}
 }
+
+#[cfg(feature = "jni")]
+#[no_mangle]
+pub unsafe extern "system" fn Java_io_parity_ethereum_Parity_configFromCli(env: JNIEnv, _: JClass, cli: jobjectArray) -> jlong {
+	let cli_len = env.get_array_length(cli).expect("invalid Java bindings");
+
+	let mut jni_strings = Vec::with_capacity(cli_len as usize);
+	let mut opts = Vec::with_capacity(cli_len as usize);
+	let mut opts_lens = Vec::with_capacity(cli_len as usize);
+
+	for n in 0 .. cli_len {
+		let elem = env.get_object_array_element(cli, n).expect("invalid Java bindings");
+		let elem_str: JString = elem.into();
+		match env.get_string(elem_str) {
+			Ok(s) => {
+				opts.push(s.as_ptr());
+				opts_lens.push(s.to_bytes().len());
+				jni_strings.push(s);
+			},
+			Err(err) => {
+				let _ = env.throw_new("java/lang/Exception", err.to_string());
+				0
+			}
+		};
+	}
+
+	let mut out = ptr::null_mut();
+	match parity_config_from_cli(opts.as_ptr(), opts_lens.as_ptr(), cli_len as usize, &mut out) {
+		0 => out as usize as jlong,
+		_ => {
+			let _ = env.throw_new("java/lang/Exception", "failed to create config object");
+			0
+		},
+	}
+}
+
+#[cfg(feature = "jni")]
+#[no_mangle]
+pub unsafe extern "system" fn Java_io_parity_ethereum_Parity_build(env: JNIEnv, _: JClass, config: jlong) -> jlong {
+	let params = ParityParams {
+		configuration: config as usize as *mut c_void,
+		.. mem::zeroed()
+	};
+
+	let mut out = ptr::null_mut();
+	match parity_start(&params, &mut out) {
+		0 => out as usize as jlong,
+		_ => {
+			let _ = env.throw_new("java/lang/Exception", "failed to start Parity");
+			0
+		},
+	}
+}
+
+#[cfg(feature = "jni")]
+#[no_mangle]
+pub unsafe extern "system" fn Java_io_parity_ethereum_Parity_destroy(_env: JNIEnv, _: JClass, parity: jlong) {
+	let parity = parity as usize as *mut c_void;
+	parity_destroy(parity);
+}
+
+#[cfg(feature = "jni")]
+#[no_mangle]
+pub unsafe extern "system" fn Java_io_parity_ethereum_Parity_rpcQueryNative<'a>(env: JNIEnv<'a>, _: JClass, parity: jlong, rpc: JString) -> JString<'a> {
+	let parity = parity as usize as *mut c_void;
+
+	let rpc = match env.get_string(rpc) {
+		Ok(s) => s,
+		Err(err) => {
+			let _ = env.throw_new("java/lang/Exception", err.to_string());
+			return env.new_string("").expect("Creating an empty string never fails");
+		},
+	};
+
+	let mut out_len = 255;
+	let mut out = [0u8; 256];
+
+	match parity_rpc(parity, rpc.as_ptr(), rpc.to_bytes().len(), out.as_mut_ptr() as *mut c_char, &mut out_len) {
+		0 => (),
+		_ => {
+			let _ = env.throw_new("java/lang/Exception", "failed to perform RPC query");
+			return env.new_string("").expect("Creating an empty string never fails");
+		},
+	}
+
+	let out = str::from_utf8(&out[..out_len])
+		.expect("parity always generates an UTF-8 RPC response");
+	match env.new_string(out) {
+		Ok(s) => s,
+		Err(err) => {
+			let _ = env.throw_new("java/lang/Exception", err.to_string());
+			return env.new_string("").expect("Creating an empty string never fails");
+		}
+	}
+}